Energy recovery unit

Abstract

Aspects relate to an energy recovery unit comprising a vessel having a condensate inlet and a condensate outlet and a fluid feed line defining a fluid path. First and second heat exchangers are located within the vessel and are arranged to transfer heat from flash vapor and condensate respectively, to fluid in the fluid feed line. The energy recovery unit can be used to recover waste energy from condensate and flash steam and use it to pre-heat process water, such as boiler feed water.

1 . An energy recovery unit, comprising:
 a vessel having a condensate inlet and a condensate outlet;   a fluid feed line defining a fluid path; and   first and second heat exchangers located within the vessel configured to transfer heat from a flash vapor and a condensate respectively, to fluid in the fluid feed line.   
     
     
         2 . An energy recovery unit according to  claim 1 , wherein the first heat exchanger is located above the second heat exchanger in the vessel. 
     
     
         3 . An energy recovery unit according to  claim 1 , wherein at least one of the first heat exchanger and the second heat exchanger comprises a plurality of heat transfer fins in thermal contact with the fluid feed line. 
     
     
         4 . An energy recovery unit according to  claim 3 , wherein the plurality of fins are stacked horizontally. 
     
     
         5 . An energy recovery unit according to  claim 1 , wherein the condensate inlet is arranged to direct condensate towards the second heat exchanger. 
     
     
         6 . An energy recovery unit according to  claim 1 , wherein the condensate outlet is located towards the bottom of the vessel. 
     
     
         7 . An energy recovery unit according to  claim 1 , wherein the condensate outlet is a first condensate outlet and the energy recovery unit further comprising:
 a second condensate outlet located above the condensate outlet.   
     
     
         8 . An energy recovery unit according to  claim 1 , wherein a condensate outlet pipe connects the condensate outlet to a steam trap. 
     
     
         9 . An energy recovery unit according to  claim 1 , further comprising a flash vapor outlet. 
     
     
         10 . An energy recovery unit according to  claim 9 , wherein the flash vapor outlet is located towards the top of the vessel. 
     
     
         11 . An energy recovery unit according to  claim 9 , wherein a flash vapor outlet pipe connects the flash vapor outlet to a pressure control valve. 
     
     
         12 . An energy recovery unit according to  claim 1 , wherein the fluid feed line passes through the vessel. 
     
     
         13 . An energy recovery unit according to  claim 12 , wherein the fluid feed path passes through at least one of the first and the second heat exchangers. 
     
     
         14 . An energy recovery unit according to  claim 1 , wherein the fluid feed line is a boiler feed line. 
     
     
         15 . An energy recovery unit, comprising:
 a flash vessel having a condensate inlet and a condensate outlet;   a fluid feed line defining a fluid path; and   a first heater exchanger located within the vessel configured to transfer a first quantity of thermal energy from a flash vapor to a fluid in the fluid feed line, such that at least a portion of the flash vapor is converted to a condensate;   a second heat exchanger located within the vessel configured to transfer a second quantity of thermal energy from the condensate to the fluid in the fluid feed line, such that the second heat exchanger;   wherein transferring the first quantity of thermal energy from the flash vapor is configured to convert at least a portion of the flash vapor to a condensate.   
     
     
         16 . An energy recovery unit according to  claim 15 , wherein the first heat exchanger is located above the second heat exchanger in the vessel and heat exchanger and the second heat exchanger each comprise a plurality of heat transfer fins in thermal contact with the fluid feed line. 
     
     
         17 . An energy recovery unit according to  claim 16 , wherein the plurality of fins are stacked horizontally substantially perpendicular to the vertical axis. 
     
     
         18 . An energy recovery unit according to  claim 17 , wherein the condensate inlet is arranged to direct condensate towards the second heat exchanger. 
     
     
         19 . An energy recovery unit according to  claim 18 , wherein the condensate outlet is located towards the bottom of the vessel. 
     
     
         20 . An energy recovery unit according to  claim 19 , wherein a condensate outlet pipe connects the condensate outlet to a steam trap.